See Plants. The Hebrew word tekheleth or sky blue of Exodus 25:4 has been viewed by some scholars as being related to a dye that was obtained from either cuttlefish; purpura snail or the janthina snail. The Talmud states that sky-blue has a certain resemblance to the colour of the indigo plant. "Sky blue" appears in the text which lists the types of offerings that the congregation are called upon to make at the Holy Ark.
The indigo shrub is a member of the pea family. It is a source for the manufacture of blue dye, and it has numerous pink flowers when in bloom.
Habitat: Dead Sea area and Tropical Africa.